Comparing the Spatial and Temporal Evolution of Land Surface Temperature and Driving Factors in Chinese 19 Urban Agglomerations
Description
China has experienced rapid expansion of urban agglomerations (UAs) in the past decades, whose negative influence affected the sustainable development of the ecological environment. However, few studies explored the long-term evolution features of these UAs and their thermal effect at the national scale by comparing UAs with different sizes. This study employed MODIS land surface temperature (LST) data to analyze the spatial and temporal evolution characteristics of LST from 2000 to 2020 and investigated its potential underlying mechanisms. The results indicated that the urban heat island (UHI) effect in urban areas was predominantly concentrated in core cities and their surrounding areas. A 10% increase in Urban Agglomeration Built-up Area Intensity (UABI) of national-level, regional-level, and city-level UAs resulted in a corresponding LST change of 1.33°C, 1.15°C, and 1.71°C, respectively, demonstrating a marginal effect. The dominant driving factors were quite different among different level UAs with the help of Geo-detector analysis. Usually, UABI and Gross Domestic Product (GDP) were the primary driving factors of LST in UAs, while Population density (POP) and Night light index (NLI) exhibited weaker effects. However, the in-tersection of UABI and Normalized Difference Vegetation Index (NDVI) has the most significant impact on LST in national-level UAs, while UABI and Digital Elevation Model (DEM) played a crucial role in both regional-level and city-level UAs. The decrease of LST was primarily influenced by the intersections of POP with NDVI. These findings aimed to provide a robust scientific and theoretical basis for mitigating the UHI effect in UAs, thereby promoting sustainable urban de-velopment.